Technical Field
The present disclosure relates to a method and a system for controlling creep torque of a vehicle to efficiently reduce brake energy and improve driving quality by preventing unnecessary creep torque in a vehicle provided with an Auto Hold function.
Description of the Related Art
The system structure of hybrid electric vehicles, electric vehicles, and fuel battery vehicles, which do not contain a torque converter, has been applied to conventional internal-combustion vehicles to enhance power transfer efficiency. The hybrid electric vehicles, electric vehicles, and fuel battery vehicles require more precise control of creep torque in order to achieve a basic level of drivability while a vehicle is slowly creeping forward.
Auto Hold, which will be discussed herein, is a convenient automotive feature that has recently been applied to an increasing number of vehicles. First, “creeping” refers, in general, to slow crawling of a vehicle caused by torque transfer resulting from fluid transfer by a torque converter turbine in an automatic transmission. Torque transfer occurs when a driver presses a brake pedal in a vehicle with an automatic transmission with the gear shift in D-position to stop the vehicle, and then takes his/her foot off the brake pedal. Therefore, the driver needs to keep pressing the brake pedal while waiting at a red light or while being stuck in a traffic jam. This may lead to fatigue or to mistakes involving the driver removing his/her foot from the brake pedal, resulting in the vehicle advancing slowly and possibly bumping into a car ahead.
Meanwhile, Auto Hold refers to a function of keeping a vehicle stationary, although the gear shift is in D-position and the driver takes his/her foot off the brake pedal after pressing the brake pedal to stop the vehicle, and then ending the stoppage of the vehicle and allowing the vehicle to move once the driver again presses the accelerator pedal.
The items above described as a related art are only for better understanding of the background of the disclosure and should not be taken as an acknowledgment that they form the related art that would already be known to a person skilled in the art.